Tire manufactures have dealt with noise problem by varying the pitch of the tread. The various formulas for the variations are generally determined differently, however. Often these variations are based on a combination of trial and error, intuition, and economics. Some manufactures have models and analogs to test tread patterns and their variations. These efforts, however practical, do not determine the best variation beforehand or guarantee the best results. For this reason it was felt that a general mathematical approach for determining the best variation was needed. Moreover, the method should be completely general, easy to use, and sufficiently accurate. This paper discusses a mathematical method called Mechanical Frequency Modulation(MFM) which meets the above requirements. Thus, MFM pertains to computing an irregular time sequence of events so that the resulting excitation spectrum is shaped to a preferred form. The first part of this paper treats the theoretical basis for computing an optimum variation ; the second part discusses experimental results and simulation program which corroborate the theory.

Abstract
 1. 서론
 2. 소음 발생기구에 관한 이론적 배경
  2.1 피치소음 발생기구
  2.2 패턴소음 발생기구
 3. 시뮬레이션 프로그램
 4. 시뮬레이션 결과 및 고찰
 5. 결론
 참고문헌

• Xiquin Adrian(원광대학교 공과대학 기계자동차공학부) | 씨퀸 아드리안
• 김병삼(원광대학교 공과대학 기계자동차공학부, 원광대학교 부설 공업기술개발연구소 연구위원) | Byoung-Sam Kim 교신저자
• 이태근(대덕대학 정밀기계시스템과) | Tae-Keun Lee
• 차화동(전북대학교대학원 산업정보시스템공학과) | Hwa-Dong Cha